Arthritis. Back pain. Not to pick a scab, but those long putters with the anchored stroke were a boon for older (and I mean 60+ yr old) golfers - bending over to practice putting with a 33" - 35" putter is no fun if you have lower back pain. I see the SG at 50 in the chart on the downslope. Less time on the practice green means more 3 putts. I think less time on the practice green makes the stroke less solid so grip changes happen to compensate. That 48" putter may come out again this year and we'll work around the rule. I can putt all day with that thing.
At least in my case my short irons and wedges became harder to practice with and my short game suffered. Enter the One Length irons and wedges. At 5'11" they're standard 5 iron length. Win.
Arthritis in the knees make the driving and approach play suffer in the 50+ yr old golfer as we still try to swing the club like we did when we were young. It's frustrating.